On Tue, Jul 14, 2020 at 05:21:08PM -0700, Daniel Miller wrote:
> Given a recipient address in the form "s123...@example.com", and I'm
> given the IP and port, do I just need to define an entry in my transport
> map? E.g.:
>
> s123...@example.com 1.2.3.4:5525
You probably won't be surprised to learn that the primary purpose of the
transport(5) table is to select a *transport* for the given lookup key.
http://www.postfix.org/transport.5.html
RESULT FORMAT
The lookup result is of the form transport:nexthop. The transport
field specifies a mail delivery transport such as smtp or local. The
nexthop field specifies where and how to deliver mail.
The transport field specifies the name of a mail delivery transport
(the first name of a mail delivery service entry in the Postfix mas-
ter.cf file).
The nexthop field usually specifies one recipient domain or hostname.
In the case of the Postfix SMTP/LMTP client, the nexthop field may con-
tain a list of nexthop destinations separated by comma or whitespace
(Postfix 3.5 and later).
The syntax of a nexthop destination is transport dependent. With SMTP,
specify a service on a non-default port as host:service, and disable MX
(mail exchanger) DNS lookups with [host] or [host]:port. The [] form is
required when you specify an IP address instead of a hostname.
A null transport and null nexthop field means "do not change": use the
delivery transport and nexthop information that would be used when the
entire transport table did not exist.
A non-null transport field with a null nexthop field resets the nexthop
information to the recipient domain.
A null transport field with non-null nexthop field does not modify the
transport information.
Therefore, the correct syntax would be either:
s123...@example.com smtp:[1.2.3.4]:5525
or
s123...@example.com :[1.2.3.4]:5525
if you wanted to keep some initial transport (based on the address
class) unmodified, while resetting just the nexthop. SMTP nexthop
syntax is described in:
http://www.postfix.org/smtp.8.html
SMTP DESTINATION SYNTAX
The Postfix SMTP+LMTP client supports multiple destinations separated
by comma or whitespace (Postfix 3.5 and later). SMTP destinations have
the following form:
domainname
domainname:port
Look up the mail exchangers for the specified domain, and con-
nect to the specified port (default: smtp).
[hostname]
[hostname]:port
Look up the address(es) of the specified host, and connect to
the specified port (default: smtp).
[address]
[address]:port
Connect to the host at the specified address, and connect to the
specified port (default: smtp). An IPv6 address must be format-
ted as [ipv6:address].
--
Viktor.
